Negative pressure injection molding plastic molding mold and method thereof

Abstract

The invention discloses a negative pressure injection plastic molding mold, comprising a movable mold, a mold core is embedded in the movable mold, a multi-stage ejection mechanism is embedded in the mold core, the multi-stage ejection mechanism is sleeved in the interior of a pressure supply sleeve, one end of the pressure supply sleeve away from the multi-stage ejection mechanism is fixedly connected with a fixed bottom plate, the fixed bottom plate is slidably connected to the movable mold, the multi-stage ejection mechanism comprises an air hole, an induction plate and an ejection rod, the ejection rod is slidably sleeved in the interior of the pressure supply sleeve, the induction plate is elastically embedded in the end of the ejection rod away from the pressure supply sleeve, the air hole is opened in the middle of the induction plate, and the device can effectively avoid the bending of the ejector pin and the damage of the plastic part during the demoulding process of the existing injection mold.

Description

Technical Field

[0001] The invention relates to the technical field of injection molds, and in particular to a negative pressure injection plastic molding mold and a method thereof. Background Art

[0002] Injection molding, also known as injection molding, is a molding method that combines injection and molding. The advantages of the injection molding method are fast production speed, high efficiency, automated operation, a wide variety of colors, shapes from simple to complex, sizes from large to small, and precise product size. The product is easy to update and can be made into parts with complex shapes. Injection molding is suitable for mass production and molding processing fields such as products with complex shapes. At a certain temperature, the completely molten plastic material is stirred by a screw, injected into the mold cavity with high pressure, and cooled and solidified to obtain a molded product. This method is suitable for mass production of parts with complex shapes and is one of the important processing methods.

[0003] Chinese patent publication CN114434738 A discloses an injection mold and a method for making the injection mold, belonging to the field of injection mold technology, including an upper mold base and a lower mold base, and the upper mold base and the lower mold base are arranged relatively, the bottom of the lower mold base is fixedly installed with a base, the inner cavity of the lower mold base is movably installed with an ejector assembly mechanism, and the top of the ejector assembly mechanism is movably installed with a filling mechanism. In the present invention, the outer abutment block of the second assembly block can use its own elastic force to support the inner cavity of the second assembly groove after abutting, and the modular assembly of the ejector body is realized through the ejector seat. At the same time, the relative axial position of the ejector body at the top of the ejector seat can be quickly adjusted in cooperation with the second assembly block on the bottom side, so as to meet the adjustment and adaptation of the ejection position of the injection mold core of different shapes, which is conducive to adapting to the injection molding of products of different specifications, and can effectively reduce the difficulty of replacement, adjustment and maintenance of the ejector of the injection mold, and meet the use needs.

[0004] Existing injection mold equipment uses an ejector pin to quickly demold a plastic part during use. However, during the demolding process, the plastic part is prone to adhesion to the ejector pin or to adhesion to the mold core, making demolding difficult or even causing the ejector pin to bend.

[0005] Therefore, it is necessary to provide a negative pressure injection molding plastic molding mold and a method thereof to solve the above technical problems. Summary of the invention

[0006] The object of the present invention is to provide a negative pressure injection plastic molding mold and a method thereof to solve the above technical problems.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a negative pressure injection molding plastic molding mold, comprising a movable mold, a mold core is embedded in the interior of the movable mold, a multi-stage ejection mechanism is embedded in the interior of the mold core, the multi-stage ejection mechanism is sleeved in the interior of a pressure supply sleeve, and the end of the pressure supply sleeve away from the multi-stage ejection mechanism is fixedly connected to a fixed bottom plate, the fixed bottom plate is slidably connected to the movable mold, the multi-stage ejection mechanism comprises an air hole, an induction plate and an ejection rod, the ejection rod is slidably sleeved in the interior of the pressure supply sleeve, the induction plate is elastically embedded in the end of the ejection rod away from the pressure supply sleeve, and the air hole is opened in the middle of the induction plate.

[0008] As a further solution of the present invention, a deflection mechanism is provided inside the ejector rod, and the deflection mechanism includes a plug-in rod, a sleeve and a plug-in groove. The plug-in rod is fixedly connected to the bottom of the sensor plate, and the plug-in groove is opened in the middle of the ejector rod. The sleeve is elastically embedded in the inner wall of the plug-in groove, and the sleeve is sleeved on the outer end surface of the plug-in rod. The inner wall of the sleeve is provided with a spiral groove, and the outer end surface of the plug-in rod is provided with a limiting slider adapted to the spiral groove.

[0009] As a further solution of the present invention, a conical surface is provided at the bottom of the plug-in rod and the sleeve, a sliding gap is provided between the plug-in rod and the sleeve, the plug-in rod is connected with the air hole and the sliding gap through the first air hole, and the sleeve is connected with the plug-in groove and the sliding gap through the second air hole.

[0010] Furthermore, one end of the second air hole is connected to the first air hole on the surface of the tapered surface.

[0011] As a further solution of the present invention, an elastic limiting mechanism is provided inside the plug-in slot, and the elastic limiting mechanism includes multiple groups of linkage cross bars that are arranged through the inner wall of the plug-in slot, one end of the linkage cross bar is provided with an inclined portion that fits with the conical surface of the bottom of the sleeve, and the end of the linkage cross bar away from the inclined portion is provided with a latch tooth, and the inner wall of the movable mold is provided with a latch groove that matches the latch tooth.

[0012] Furthermore, the outer end surface of the linkage cross bar is fixedly sleeved with a sliding cavity, the ejector rod is provided with a sliding cavity adapted to the sliding cavity, the sliding cavity is elastically arranged inside by a sleeve plate, and the ejector rod is provided with an elastic piece adapted to the linkage cross bar.

[0013] As a further solution of the present invention, a pressure supply chamber adapted to the ejection rod is provided inside the pressure supply sleeve, and a one-way valve plate for controlling the one-way flow of airflow to the sliding gap is elastically embedded in the conical surface at the bottom of the sleeve, and an inclined groove adapted to the inclined portion is provided on the conical surface of the bottom of the sleeve, one end of the second air hole is connected to the interior of the second air hole, and the first air hole and the second air hole are staggered when the plug-in rod and the sleeve are in fit.

[0014] Furthermore, the cross section of the one-way valve plate is a trapezoid. The one-way valve plate is elastically embedded at the bottom of the conical surface.

[0015] As a further solution of the present invention, a magnetic sheet is provided on the side of the one-way valve plate away from the conical surface, a positioning column is provided in the middle of the pressure supply chamber, and a magnetic attraction mechanism is provided on the end of the positioning column away from the pressure supply chamber.

[0016] Furthermore, the magnetic attraction mechanism may adopt an electromagnetic sheet or a strong magnet.

[0017] A method for negative pressure injection molding plastic molding mold, after the movable mold injection is completed, by sliding the movable mold toward a fixed bottom plate, a multi-stage ejection mechanism protrudes from the mold core surface, and then the plastic part on the mold core surface is ejected.

[0018] When the present invention is used, in order to avoid the adhesion of the mold core leading to a large material return resistance of the multi-stage ejection mechanism, which leads to the bending of the multi-stage ejection mechanism, etc., an induction plate is provided, the induction plate is elastically connected to the ejection rod, and an air hole is provided in the middle of the induction plate. When the resistance of the induction plate is large, the induction plate will be compressed to avoid bending of the multi-stage ejection mechanism. The middle of the induction plate is provided with an air hole, and gas is discharged through the air hole to avoid adhesion of the plastic part to the surface of the induction plate, and the airflow helps to detach the plastic part. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0020] Figure 1 It is a schematic diagram of the structure of the present invention;

[0021] Figure 2 It is a schematic diagram of the fixed bottom plate structure of the present invention;

[0022] Figure 3 It is a schematic diagram of the structure of the multi-stage ejection mechanism of the present invention;

[0023] Figure 4 The present invention Figure 3 The enlarged structural diagram at A in the middle;

[0024] Figure 5 It is a structural schematic diagram of the ejector rod of the present invention in the energy storage state;

[0025] Figure 6 The present invention Figure 5 The enlarged structural diagram at B in the middle;

[0026] Figure 7 It is a schematic diagram of the distribution structure of the linkage cross bar of the present invention;

[0027] Figure 8 It is a schematic diagram of the cross-sectional structure of the casing of the present invention;

[0028] Fig. 9 It is a schematic diagram of the structure of the splice rod of the present invention;

[0029] Fig.10 The present invention Figure 7 Enlarged structural diagram at point C in the middle.

[0030] In the figure: 1. movable mold; 2. mold core; 3. multi-stage ejector mechanism; 4. fixed bottom plate; 5. pressure supply sleeve; 6. air hole; 7. induction plate; 8. ejector rod; 9. plug-in rod; 10. sleeve; 11. plug-in slot; 13. positioning column; 14. pressure supply cavity; 15. magnetic suction mechanism; 16. spiral groove; 17. first air hole; 18. sliding gap; 19. conical surface; 20. one-way valve plate; 21. inclined portion; 22. linkage cross bar; 23. latching teeth; 24. second air hole; 25. latching slot; 26. limit slider; 28. inclined slide groove; 29. ​​magnetic sheet; 30. elastic member; 31. sleeve plate; 32. sliding cavity; 33. groove. DETAILED DESCRIPTION

[0031] Embodiment 1

[0032] like Figure 1 - Figure 3 As shown, a negative pressure injection plastic molding mold comprises a movable mold 1, a mold core 2 is embedded in the movable mold 1, a multi-stage ejection mechanism 3 is embedded in the mold core 2, the multi-stage ejection mechanism 3 is sleeved in the inside of a pressure supply sleeve 5, and the end of the pressure supply sleeve 5 away from the multi-stage ejection mechanism 3 is fixedly connected to a fixed bottom plate 4, and the fixed bottom plate 4 is slidably connected to the movable mold 1. The multi-stage ejection mechanism 3 comprises an air hole 6, an induction plate 7 and an ejection rod 8, the ejection rod 8 is slidably sleeved in the inside of the pressure supply sleeve 5, the induction plate 7 is elastically embedded in the end of the ejection rod 8 away from the pressure supply sleeve 5, and the air hole 6 is opened in the middle of the induction plate 7.

[0033] When in use, after the injection molding of the movable mold 1 is completed, the movable mold 1 is slid toward the fixed bottom plate 4 so that the multi-stage ejector mechanism 3 protrudes from the surface of the mold core 2, and then the plastic parts on the surface of the mold core 2 are ejected. In order to avoid the adhesion of the mold core 2, which leads to a large material withdrawal resistance of the multi-stage ejector mechanism 3 and causes the multi-stage ejector mechanism 3 to bend, etc., an induction plate 7 is provided, and the induction plate 7 is elastically connected to the ejection rod 8, and an air hole 6 is provided in the middle of the induction plate 7. When the resistance of the induction plate 7 is large, the induction plate 7 will be compressed to avoid the multi-stage ejector mechanism 3 from bending, and the air hole 6 is provided in the middle of the induction plate 7. The gas discharged through the air hole 6 can avoid the adhesion of the plastic parts to the surface of the induction plate 7, and the air flow also helps to detach the plastic parts.

[0034] like Figure 1 - Figure 4 and Figure 8-9As shown, a deflection mechanism is provided inside the ejector rod 8, and the deflection mechanism includes a plug-in rod 9, a sleeve 10 and a plug-in groove 11. The plug-in rod 9 is fixedly connected to the bottom of the induction plate 7, and the plug-in groove 11 is opened in the middle of the ejector rod 8. The sleeve 10 is elastically embedded in the inner wall of the plug-in groove 11, and the sleeve 10 is sleeved on the outer end surface of the plug-in rod 9. The inner wall of the sleeve 10 is provided with a spiral groove 16, and the outer end surface of the plug-in rod 9 is provided with a limiting slider 26 adapted to the spiral groove 16.

[0035] During use, as the movable mold 1 moves, the induction plate 7 gradually comes into contact with the plastic part on the surface of the movable mold 1. As the induction plate 7 comes into contact with the movable mold 1, the induction plate 7 drives the plug-in rod 9 to move inside the sleeve 10. Since the side end face of the plug-in rod 9 is provided with a spiral groove 16, the plug-in rod 9 can rotate when it moves vertically through the limiting slider 26 and the spiral groove 16 under the elastic limitation of the sleeve 10, thereby avoiding the adhesion of the induction plate 7 to the plastic part and improving the demoulding effect of the induction plate 7 on the movable mold 1.

[0036] like Figure 1 - Figure 4 and Figure 8-9 As shown, a conical surface 19 is provided at the bottom of the plug rod 9 and the sleeve 10, a sliding gap 18 is provided between the plug rod 9 and the sleeve 10, the plug rod 9 is connected with the air hole 6 and the sliding gap 18 through the first air hole 17, and the sleeve 10 is connected with the plug groove 11 and the sliding gap 18 through the second air hole 24.

[0037] Furthermore, one end of the second air hole 24 and the first air hole 17 are connected on the surface of the tapered surface 19 .

[0038] During use, as the plug-in rod 9 moves downward, the space between the plug-in rod 9 and the sliding gap 18 gradually shrinks, so that the gas in the sliding gap 18 enters the interior of the air hole 6 through the first air hole 17, so that the air hole 6 does not need an additional gas source input, and the movement of the sensing plate 7 can generate a micro-airflow that helps to separate the sensing plate 7 from the plastic part.

[0039] like Figure 1 - Figure 7 and Fig.10 As shown, an elastic limiting mechanism is provided inside the plug-in slot 11, and the elastic limiting mechanism includes a plurality of linkage cross bars 22 penetrating the inner wall of the plug-in slot 11, one end of the linkage cross bar 22 is provided with an inclined portion 21 that fits with the inclined surface of the conical surface 19 at the bottom of the sleeve 10, and the end of the linkage cross bar 22 that is away from the inclined portion 21 is provided with a latching tooth 23, and the inner wall of the movable mold 1 is provided with a latching groove 25 that is compatible with the latching tooth 23.

[0040] Furthermore, the outer end surface of the linkage cross bar 22 is fixedly sleeved with a sliding cavity 32, the ejector rod 8 is provided with a groove 33 adapted to the sliding cavity 32, the sliding cavity 32 is elastically arranged inside the groove 33 through a sleeve plate 31, and the ejector rod 8 is provided with an elastic member 30 adapted to the linkage cross bar 22.

[0041] When in use, the linkage cross bar 22 is elastically embedded in the ejector rod 8, and one end of the linkage cross bar 22 is elastically fitted with the sleeve 10, and the sleeve 10 is limited in the inside of the plug-in groove 11 under the action of the inclined surface. When the induction plate 7 is pressed until the plug-in rod 9 is fitted with the sleeve 10, if the induction plate 7 and the movable mold 1 have not been separated at this time, it means that the plastic part and the mold core 2 are strongly adhered, and forced material withdrawal may cause damage to the plastic part or bending of the multi-stage ejection mechanism 3, and then a linkage cross bar 22 is provided. When the plug-in rod 9 is fitted with the sleeve 10, the induction plate 7 continues to be pressed, and the plug-in rod 9 will drive the sleeve The tube 10 continues to move, and under the action of the conical surface 19 at the bottom of the sleeve 10 and the inclined surface of the inclined surface 21, the linkage cross bar 22 is pushed to move horizontally relative to the ejector rod 8 and extend through the ejector rod 8 so that the outer surface of the ejector rod 8 fits the inner wall of the movable mold 1. At the same time, a latch tooth 23 is provided at the end of the linkage cross bar 22. After the latch tooth 23 and the latch groove 25 are locked and limited, the ejector rod 8 can move synchronously with the movable mold 1 at this time, so that the induction plate 7 and the plastic part are relatively stationary in this state, and the supporting force of the induction plate 7 on the plastic part is no longer increased, thereby avoiding the damage of the plastic part and the bending of the multi-stage ejection mechanism 3.

[0042] like Figure 1 - Fig. 9 As shown, a pressure supply cavity 14 adapted to the ejector rod 8 is provided inside the pressure supply sleeve 5, and a one-way valve plate 20 for controlling the one-way flow of air to the sliding gap 18 is elastically embedded in the conical surface 19 at the bottom of the sleeve 10, and an inclined groove 28 adapted to the inclined portion 21 is provided on the surface of the conical surface 19 at the bottom of the sleeve 10, and one end of the second air hole 24 is connected to the interior of the second air hole 24, and the first air hole 17 and the second air hole 24 are staggered when the plug-in rod 9 and the sleeve 10 are in contact.

[0043] Furthermore, the cross section of the one-way valve plate 20 is a trapezoid. The one-way valve plate 20 is elastically embedded at the bottom of the conical surface 19 .

[0044] When in use, when the ejector rod 8 moves synchronously with the movable mold 1, as the ejector rod 8 continues to move, the bottom of the ejector rod 8 is closed, so that the pressure inside the pressure supply chamber 14 continues to increase, and a one-way valve plate 20 and an inclined slide groove 28 are provided. The end of the linkage cross bar 22 is slidably connected to the inside of the inclined slide groove 28, which can also prevent the sleeve 10 from rotating synchronously with the plug-in rod 9 inside the plug-in groove 11. There are two situations during operation. When the induction plate 7 is adhered to the plastic part, the plug-in rod 9 and the sleeve 10 cannot rotate. At this time, the plug-in rod 9 will directly drive the sleeve 10 moves downward, so that the linkage cross bar 22 extends out. When the linkage cross bar 22 extends out, the inclined portion 21 moves relative to the inclined slide groove 28. When the linkage cross bar 22 fits with the movable mold 1, the linkage cross bar 22 closes the second air hole 24 inside the inclined slide groove 28, so that the bottom of the ejector rod 8 is closed. If the induction plate 7 is not adhered to the plastic part, but the plastic part is strongly adhered to the mold core 2, the plug-in rod 9 and the sleeve 10 fit together at this time, so that the sliding gap 18 disappears. At this time, the first air hole 17 and the second air hole 24 are staggered, so that the bottom of the ejector rod 8 can also be closed.

[0045] like Figure 1 - Fig. 9 As shown, a magnetic sheet 29 is provided on the side of the one-way valve plate 20 away from the conical surface 19 , a positioning column 13 is provided in the middle of the pressure supply chamber 14 , and a magnetic attraction mechanism 15 is provided on the end of the positioning column 13 away from the pressure supply chamber 14 .

[0046] Furthermore, the magnetic attraction mechanism 15 may be an electromagnetic sheet or a strong magnet.

[0047] During use, when the internal pressure of the pressure supply chamber 14 accumulates to an appropriate value, the one-way valve plate 20 gradually approaches the positioning column 13 as the ejector rod 8 moves. When the distance between the one-way valve plate 20 and the pressure supply chamber 14 decreases, the suction force of the magnetic attraction mechanism 15 on the magnetic sheet 29 increases. When the distance is close enough, the one-way valve plate 20 is separated from the conical surface 19, so that the accumulated pressure in the pressure supply chamber 14 enters the sliding gap 18 through the one-way valve plate 20 and impacts the surface of the plastic part through the air hole 6, so that the plastic part is separated from the mold core 2, and the impact pressure can be adaptively controlled by controlling the magnetic force of the magnetic attraction mechanism 15. After separation, the sensing plate 7 and the sleeve 10 will be reset, waiting for the next material return.

[0048] A method for negative pressure injection molding plastic molding mold, after the movable mold 1 is injection-molded, the movable mold 1 is slid toward the fixed bottom plate 4, so that the multi-stage ejection mechanism 3 protrudes from the surface of the mold core 2, and then the plastic part on the surface of the mold core 2 is ejected.

[0049] Working principle: After the injection molding of the movable mold 1 is completed, the movable mold 1 is slid toward the fixed bottom plate 4 so that the multi-stage ejector mechanism 3 protrudes from the surface of the mold core 2, and then the plastic parts on the surface of the mold core 2 are ejected. In order to avoid the adhesion of the mold core 2, which leads to the large material withdrawal resistance of the multi-stage ejector mechanism 3 and the bending of the multi-stage ejector mechanism 3, etc., an induction plate 7 is provided, and the induction plate 7 is elastically connected to the ejection rod 8, and an air hole 6 is provided in the middle of the induction plate 7. When the resistance of the induction plate 7 is large, the induction plate 7 is compressed to avoid the bending of the multi-stage ejector mechanism 3, and the air hole 6 is provided in the middle of the induction plate 7. The gas discharged through the air hole 6 can avoid the adhesion of the plastic parts to the surface of the induction plate 7, and the air flow helps the detachment of the plastic parts. As the movable mold 1 moves, the induction plate 7 gradually contacts the plastic parts on the surface of the movable mold 1. The plate 7 is in contact with the movable mold 1, and the induction plate 7 drives the plug rod 9 to move inside the sleeve 10. Since the side end surface of the plug rod 9 is provided with a spiral groove 16, the plug rod 9 can rotate when the vertical movement is performed by the limit slider 26 and the spiral groove 16 under the elastic limit of the sleeve 10, thereby avoiding the adhesion of the induction plate 7 to the plastic part and improving the demoulding effect of the induction plate 7 on the movable mold 1. As the plug rod 9 moves downward, the space between the plug rod 9 and the sliding gap 18 is gradually reduced, so that the gas in the sliding gap 18 enters the interior of the air hole 6 through the first air hole 17, so that the air hole 6 does not need an additional gas source input, and a micro-airflow that helps to separate the induction plate 7 from the plastic part can be generated by the movement of the induction plate 7, and the linkage cross bar 22 is elastically embedded in the ejection rod 8, and one end of the linkage cross bar 22 is elastically fitted with the sleeve 10, and the sleeve 10 is limited in the inside of the plug-in groove 11 under the action of the inclined surface. When the induction plate 7 is pressed until the plug-in rod 9 is fitted with the sleeve 10, if the induction plate 7 and the movable mold 1 have not been separated at this time, it means that the plastic part and the mold core 2 are strongly adhered, and forced material withdrawal may cause damage to the plastic part or bending of the multi-stage ejection mechanism 3, and then a linkage cross bar 22 is provided. When the plug-in rod 9 is fitted with the sleeve 10, the induction plate 7 continues to be pressed, and the plug-in rod 9 will drive the sleeve 10 to continue to move. Under the action of the tapered surface 19 at the bottom of the sleeve 10 and the inclined surface of the inclined portion 21, the linkage cross bar 22 will be pushed to move horizontally relative to the ejector rod 8 and extend through the ejector rod 8. The outer surface of the ejector rod 8 is fitted with the inner wall of the movable mold 1, and at the end of the linkage cross bar 22 A latching tooth 23 is provided, and after the latching tooth 23 is locked and limited with the latching groove 25, the ejector rod 8 can move synchronously with the movable mold 1 at this time, so that the induction plate 7 and the plastic part are relatively still in this state, and the supporting force of the induction plate 7 on the plastic part is no longer increased, thereby avoiding the problem of damage to the plastic part and bending of the multi-stage ejection mechanism 3. When the ejector rod 8 moves synchronously with the movable mold 1, as the ejector rod 8 continues to move, the bottom of the ejector rod 8 is closed, so that the internal pressure of the pressure supply chamber 14 continues to increase, and a one-way valve plate 20 and an inclined groove 28 are provided. The end of the linkage cross bar 22 is slidably connected to the inside of the inclined groove 28, which can also prevent the sleeve 10 from rotating synchronously with the plug-in rod 9 in the plug-in groove 11. There are two situations during operation. When the induction plate 7 is adhered to the plastic part and the plug-in rod 9 and the sleeve 10 cannot rotate,At this time, the plug-in rod 9 will directly drive the sleeve 10 to move downward, so that the linkage cross bar 22 extends out. When the linkage cross bar 22 extends out, the inclined portion 21 moves relative to the inclined slot 28. When the linkage cross bar 22 fits with the movable mold 1, the linkage cross bar 22 closes the second air hole 24 inside the inclined slot 28, so that the bottom of the ejector rod 8 is closed. If the induction plate 7 is not adhered to the plastic part, but the plastic part is strongly adhered to the mold core 2, the plug-in rod 9 fits with the sleeve 10, so that the sliding gap 18 disappears. At this time, the first air hole 17 and the second air hole 24 are staggered, so that the bottom of the ejector rod 8 can also be closed. When the pressure inside the pressure supply chamber 14 When the pressure accumulates to a suitable value, the one-way valve plate 20 gradually moves closer to the positioning column 13 as the ejector rod 8 moves. When the distance between the one-way valve plate 20 and the pressure supply chamber 14 decreases, the magnetic attraction mechanism 15 increases the attraction force on the magnetic sheet 29. When the distance is close enough, the one-way valve plate 20 separates from the conical surface 19, so that the pressure accumulated in the pressure supply chamber 14 enters the sliding gap 18 through the one-way valve plate 20 and impacts the surface of the plastic part through the air hole 6, so that the plastic part is separated from the mold core 2. The impact pressure can be adaptively controlled by controlling the magnetic force of the magnetic attraction mechanism 15. After separation, the induction plate 7 and the sleeve 10 will be reset and wait for the next material withdrawal.

Claims

1. A negative pressure injection molding plastic molding mold, comprising a movable mold, wherein a mold core is embedded in the movable mold, characterized in that: A multi-stage ejection mechanism is embedded in the mold core, and the multi-stage ejection mechanism is sleeved in the pressure supply sleeve. One end of the pressure supply sleeve away from the multi-stage ejection mechanism is fixedly connected to a fixed bottom plate, and the fixed bottom plate is slidably connected to the movable mold. The multi-stage ejection mechanism includes an air hole, a sensing plate and an ejection rod. The ejection rod is slidably sleeved in the pressure supply sleeve, and the sensing plate is elastically embedded in one end of the ejection rod away from the pressure supply sleeve, and the air hole is opened in the middle of the sensing plate; A deflection mechanism is provided inside the ejector rod, and the deflection mechanism includes a plug-in rod, a sleeve and a plug-in slot. The plug-in rod is fixedly connected to the bottom of the induction plate, and the plug-in slot is opened in the middle of the ejector rod. The sleeve is elastically embedded in the inner wall of the plug-in slot, and the sleeve is sleeved on the outer end surface of the plug-in rod. The inner wall of the sleeve is provided with a spiral groove, and the outer end surface of the plug-in rod is provided with a limit slider adapted to the spiral groove; The bottoms of the plug rod and the sleeve are provided with conical surfaces, a sliding gap is provided between the plug rod and the sleeve, the plug rod is connected with the air hole and the sliding gap through the first air hole, and the sleeve is connected with the plug slot and the sliding gap through the second air hole.

2. A negative pressure injection molding plastic molding mold according to claim 1, characterized in that: An elastic limiting mechanism is provided inside the plug-in slot, and the elastic limiting mechanism includes multiple groups of linkage cross bars that are arranged through the inner wall of the plug-in slot, one end of the linkage cross bar is provided with an inclined portion that fits with the conical surface inclined surface of the bottom of the sleeve, and the end of the linkage cross bar that is away from the inclined portion is provided with a latch tooth, and the inner wall of the movable mold is provided with a latch groove that is adapted to the latch tooth.

3. A negative pressure injection molding plastic forming mold according to claim 2, characterized in that: A pressure supply cavity adapted to the ejection rod is provided inside the pressure supply sleeve, and a one-way valve plate for controlling the one-way flow of airflow to the sliding gap is elastically embedded on the conical surface at the bottom of the sleeve.

4. A negative pressure injection molding plastic forming mold according to claim 3, characterized in that: The conical surface at the bottom of the sleeve is provided with an inclined groove matched with the inclined portion, one end of the second air hole is connected to the inside of the second air hole, and the first air hole and the second air hole are staggered when the plug rod is fitted with the sleeve.

5. A negative pressure injection molding plastic forming mold according to claim 4, characterized in that: A magnetic sheet is provided on the side of the one-way valve plate away from the conical surface, a positioning column is provided in the middle of the pressure supply chamber, and a magnetic attraction mechanism is provided on the end of the positioning column away from the pressure supply chamber.

6. A negative pressure injection molding plastic molding method, using the negative pressure injection molding plastic molding mold according to any one of claims 1 to 5, characterized in that: After the injection molding of the movable mold is completed, the movable mold is slid toward the fixed bottom plate so that the multi-stage ejection mechanism protrudes from the surface of the mold core, thereby ejecting the plastic parts on the surface of the mold core.

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